Sports Nutrition & Performance

SN&P integrates nutrisci, physio, metablo, & train mod to optimize AT, EN, & recov. Core obj: max EEx, sustain O2 cost, delay fatig, enhance adpt. Fundamentals: EN bal (CI - EE = bal), macronutr (CHO, PRO, Lip), micronutr (Fe, Vit D, Ca, Mg), hydr status. CHO = primary fuel dur HIIT & endur. Glycogen stor (~500g liv, ~400g musc) dict perf; deple → bonk. Recom: 6–10g/kg/d CHO for mod-train, up to 12g/kg/d peak load. Glycogen synth: rate-limited by GSase act, insulin sens, timing. STRAT: CHO load (deplet-foad obsolete), taper + 8–12g/kg/d x3–4d → ~900g stor. PRO: supp myo synth (MPS), inhib myo prot break (MPB). Recom: 1.6–2.2g/kg/d for AT, PPRO post-ex (0.3g/kg + 0.1g/kg CHO) → max MPS. EAA, leu (≥2.5g) trigger mTORC1. Casein (slow) vs whey (fast) → timing diff. Lip: ≥1.0g/kg/d; fuel in LIT, supps horm prod, cell integ. MUFA/PUFA > SFA; ω-3 (EPA/DHA) ↓ inflam, ↑ recov. Hydr: sweat rate (SR) var (0.5–2.5L/h), Na+ loss (200–1500mg/L). Dehyd >2% BW → ↓ CO, ↑ temp, ↓ cogn perf. STRAT: pre-hydr, intra (4–8% glu-sol, Na+ 20–30mmol/L), post (150% fluid + Na+). Na+ co-tran → ↑ H2O upt. Electrolytes: Na+, K+, Mg2+, Ca2+ → nerve, cont, hydr. Mg def → cramp, ↓ glycol. Micronutrs: Fe (Hb synth, O2 trans), ↑ req in fem, run. Def → IDA → ↓ VO2max. Supp if ferritin <30μg/L. Vit D: immun mod, musc fxn, recov; def → ↑ inj risk. Recom: 1000–4000 IU/d, opt if <30ng/mL. Ca: bone health, cont; ≥1000mg/d. Antiox: high-dose supp (Vit C/E) may ↓ mito biog (ROS signl imp), impair train adpt. Prefer food-sourced (berries, nuts). Nutr timing: peri-ex window (pre, intra, post) manip metablo state. Pre: 1–4h prior, mod-glyc index CHO + PRO → sust EN, ↓ MPB. Intra: >75min ex → 30–60g/h CHO (multi-transp: glu+fru → ↑ ox rate). Post: 0–2h crit for glycogen resyn (insulin sens ↑), PRO intak → ↑ MPS. 1.2g/kg CHO + 0.3g/kg PRO → max resyn rate. Fast: IF (e.g., 16:8) may ↑ fat ox, glycogen sparing; but ↓ HI perf, AT adapt if mal-timed. Train-low-compete-high: per-coop ↑ mito dens, fat ox; but ↑ MPB, ↓ train qual if freq high. Not for peaking. GI issues: common in endur; ↓ BF, ↑ splanchnic ischem → ischem-reperfusion inj. STRAT: train GI (grad expos to carb/fluid), ↓ FODMAP pre-race, use multi-CHO. Supps: ergogen aids w/ ev (ISSN): CrM (5g/d x5d load → ↑ PCr, ↑ reps, ↑ V̇O2peak), Caff (3–6mg/kg pre → ↑ FA ox, ↓ RPE, ↑ focus), β-Ala (3–6g/d x4w → ↑ carnosine → buff H+ → ↓ acidosis), Nitrate (beet juc, 5–9mmol NO3− → ↑ NO → ↓ O2 cost → ↑ eff), HMB (↓ MPB, recov). Controv: BCAA (redundant w/ full PRO), colloid (no evid), TST (doping). Pitfalls: over-reliance on supp, underfueling (RED-S: low EA → ↓ metablo rate, ↓ bone, ↓ lib, amenorrhea), overhydr (hyponatremia), poor timing, ignoring indiv var. RED-S: energy avail (EA = CI - EE) <30kcal/kg FFM → endocrine dysreg → long-term dam. Screen: wt loss, fatig, inj, menstr dysf. Diag: history, labs. Man: ↑ CI, ↓ train load. Gut-musc axis: micrbiot mod inflam, metablo, recov. High-fiber, div diet ↑ SCFA → ↓ TNF-α. Probiot: strain-spec (e.g., PB8, L. helveticus) → ↓ URI, ↑ perf. Monitoring: BW (acute Δ = fluid), Usg (pre-void: <1.020 euhydr), food logs, bloodwork (Fe, Vit D, inflam). Tools: DEXA (body comp), RMR (rest metablo rate), sweat test (Na+ loss). Fut: nutrigenom (gene-diet interac e.g., ACTN3, IL6), micro-nutr metablotyping, AI-driven perz diet. Apps: MyFitnessPal, Cronometer, TrainAsONE. Key: indv diff (genet, metablo flex, sport specif, sex diff) → no one-size. Princ: food first, periodize nutr match train cycle (base, build, peak, taper), align w/ perf goals.